[swift-evolution] Passing an optional first argument to sequence(first:next:)

[Tim Vermeulen]

sequence(first:next:) takes a non-optional first argument. Is there a reason for that? sequence(state:next:) allows empty sequences, and I don’t see why sequence(first:next:) shouldn’t. The fix would be to simply add the `?` in the function signature; no other changes are required to make it work.

I considered just filing a bug report, but since this is a change of the public API...